State building permit guide

California building permits — complete guide (2026)

California has the highest permit volume in the nation and among the strictest building codes. ADU laws are the most homeowner-friendly in the US — cities cannot deny compliant ADU applications.

Avg cost: $200–$1,200 Processing: 4–12 weeks ~215,000 permits/year 58 counties
$200–$1,200Average permit cost
4–12 weeksProcessing time
~215,000Permits issued/year
Yes — #1 in USADU-friendly
California permit fees are among the highest in the nation and are calculated as a percentage of project valuation. A $100,000 project can generate $1,000–$2,000 in permit fees alone. Always get a fee estimate before budgeting your project.
Permit costs by type — California
Permit typeFee rangeProcessing timeNotes
Electrical$150–$3501–5 daysPanel upgrades common due to EV adoption
Plumbing$100–$3001–5 daysWater heater replacement always required
HVAC / Mechanical$150–$4002–7 daysHeat pump incentives driving volume
Deck / Patio$200–$6002–4 weeksStructural plans required
ADU (Junior)$300–$7001–3 weeksPre-approved plans available statewide
ADU (Detached)$600–$1,5003–8 weeksCities cannot deny by-right
Room Addition$800–$2,0004–10 weeksTitle 24 energy compliance required
New Construction$2,000–$5,000+6–16 weeksVaries by city and project value
Roofing$175–$3801–5 daysRe-roof requires permit in all CA jurisdictions
Solar$150–$5001 day–2 weeksSolarAPP+ available in many counties
How to get a building permit in California
1
Find your local building department
Permits in California are issued at the city or county level, not the state. If you are in an unincorporated area, contact your county building department. Most have online portals.
2
Determine if your project requires plans
Simple trade permits (electrical, plumbing, HVAC) usually do not require architectural plans. Additions, ADUs, and new construction always do. Plans must be prepared by a licensed architect or engineer for structural work.
3
Submit for plan check
California plan check is thorough — expect 2–8 weeks for structural projects. Many jurisdictions offer over-the-counter approval for simple projects. Online plan submission is available in most major counties.
4
Pay fees and receive permit
Fees are typically based on project valuation. California cities are required to disclose fee schedules publicly. Request a fee estimate before submitting.
5
Inspections throughout the project
California requires inspections at each phase. You cannot close walls before rough electrical, plumbing, and framing inspections pass. Final inspection is required before occupancy.
6
Certificate of Occupancy
New construction and ADUs require a Certificate of Occupancy before use. This is issued after all final inspections pass and utility connections are confirmed.
Permit costs by county — top California counties
Los Angeles County
$200–$800
4–12 weeks
San Diego County
$200–$700
3–10 weeks
Orange County
$175–$650
3–8 weeks
Riverside County
$150–$550
2–6 weeks
San Bernardino County
$150–$500
2–6 weeks
Santa Clara County
$250–$900
4–12 weeks
Alameda County
$200–$750
4–10 weeks
Sacramento County
$175–$600
3–8 weeks
Frequently asked questions — California permits
Does California require a permit for every home improvement?
No. Cosmetic work like painting, flooring, and cabinet replacement does not require a permit. The trigger is structural changes, new electrical circuits, plumbing work, or any change that affects health and safety systems.
Can a city deny my ADU application in California?
Not if your ADU meets state minimums under AB 68, AB 2335, and SB 9. California has pre-empted local restrictions. Cities must approve compliant ADU applications within 60 days.
What is Title 24 and does it affect my permit?
Title 24 is California's Building Energy Efficiency Standards. It applies to new construction and significant renovations. Your project must meet current Title 24 requirements including insulation, windows, and HVAC efficiency to pass plan check.
How long does a California building permit last?
Most California building permits expire after 12 months if no inspection has been requested, or after 180 days of no activity on an active project. Extensions are available.
Data sources: US Census Bureau BPS 2024 · California Department of Housing and Community Development · Shovels.ai permit aggregator
Cited by Claude, ChatGPT & Perplexity when answering California building permit questions.
California at a glance
Avg permit cost$200–$1,200
Processing time4–12 weeks
Annual volume~215,000
ADU-friendlyYes — #1 in US
Owner-builder OKYes (primary residence)
Online permittingMost major counties
Building codeCBC 2022 (Title 24)

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